Ductwork that is used for circulating air in heating and air conditioning systems usually includes a series of box-shaped sections connected together to form a duct of the desired length. Each of the box-shaped sections has a flange extending transversely outwardly from each side at each end of the section to provide for connection of one section to another completed section. The sections are connected at each of the corners of the flanges by placing a standard corner piece along the flanges of each section and then forcing this corner piece down into the flanges after which the outer edges of the flanges are crimped over the corner piece to retain it in place. The corner pieces are then bolted or otherwise connected together to join the two sections. At the present time, the corner pieces are installed by using a hammer to pound the corner piece into place on the flanges, and then the outer edge of the flanges are hammered over to hold the corner piece in place. There are also available tools resembling large pliers or tongs which can be used to force the corner piece onto the flanges and then used to crimp over the outer edges of the flanges to hold the corner piece in place. Obviously, even in the hands of a skilled user, these are somewhat slow and cumbersome procedures for installing the corners of a box section. Especially when heavier gauges of sheet metal are used in the making the ducts, it requires a considerable amount of strength and is quite tiresome to repeatedly perform these operations.
Therefore, there is a need for a way to more quickly perform the corner installation operation, thus producing a substantial savings in labor costs. Moreover, there is a further need to provide an improved and better way of performing these operations with less fatigue to the worker while at the same time providing a quality installation.